The 'digital death' campaign, created by TBWA Chiat Day New York, involves a number of high profile celebrities signing off from all social networking platforms, including Twitter and Facebook.
Participating celebrities will rejoin the networks when US$1 million has been collectively raised for the charity, which works to raise awareness about the number of individuals dying from Aids every day.
The Twitter accounts will direct fans to the celebrities' personal pages on Buylife.org where the famous contributers have posted a "last tweet and testament video" to encourage online and text donations.
In addition, the celebrities will be posting images of themselves lying in coffins to symbolise their digital death.
Well-known faces taking part include Usher, Serena Williams, Kim Kardashian and Elijah Wood.
